GUI Instantly disappears In ROBLOX after death, but it works in Studio? I think its because of FE.

I created a script where you the player pick a class on spawn. And after picking the class the GUI goes away. But after you die the GUI is SUPPOSED to re-appear, it does but only in Studio. In normal ROBLOX the GUI re-appears for less than a second and goes away in a flash. When I turn off FE it works fine. So anyone got any ideas?

Heres the script

player = game.Players.LocalPlayer
button = script.Parent:FindFirstChild("Play")
storage = game.StarterPack

button.MouseButton1Click:connect(function()
    local Pistol = storage:FindFirstChild("Pistol")
    player.Backpack.Pistol:Destroy()
    player.PlayerGui:FindFirstChild("ClassGUI").Enabled = false
        player.Character:WaitForChild("Humanoid").Died:connect(function()
            local ClassGui = script.Parent.Parent
            ClassGui:Clone().Parent = player.PlayerGui
            wait(5)
            ClassGui.Enabled = true
        print("Nope")
    end)
end)

Thanks for your time :)